During the past four years a Psychiatric Epidemiology Study of mental disorders in Puerto Rico has been conducted with the purpose of obtaining systematic data about rates of psychiatric disorders. A supplemental application to the above mentioned study was funded in January 1987 by N.I.M.H. to study the psychological impact of a disaster (torrential rains and mudslides) which occurred in Puerto Rico in 1985. The present application takes advantage of the opportunity to study drug abuse and dependence as a part of this on-going project; it requests additional funding for an in depth study of drug addiction in Puerto Rico. We propose to conduct descriptive analysis of the symptoms associated to drug addiction in a probability sample of Puerto Rico, and generate estimates of the prevalence of drug abuse and/or dependence. To accomplish these aims, we plan to translate into Spanish, adapt and test in the Puerto Rican culture the Composite International Diagnostic Interview Schedule- Substance Abuse Module (outcome variable) and Anti Social Personality Schedule of the DIS (a documented risk factor). The capacity to detect significant differences will be enhanced by increasing the sample size of the original disaster grant (N-800) to be a total sample size of 900 by oversampling the population in the 17 to 20 age range. The proposed increment to our sample base will permit a detailed study of drug abuse/dependence symptomatology in Puerto Rico. The oversampling of a segment of the population that is at higher risk (the age group between 17 to 20 years), will provide greater statistical power in the analysis contemplated. Whereas, the funding requested from N.I.D.A. will be used to increment our base sample, the net result will be an extensive study of drug abuse on a sample of 900. The advantage to be derived from the supplemental funding requested is that it will allow a comprehensive study at minimal cost, given that the funding for the core study will be available through the NIMH disaster grant. If a study of this scope and breadth were to be conducted on a sample of this size, costs would doubtlessly increase sixfold.